Organic light emitting diode (OLED) is an organic film electroluminescent device with advantages such as simple fabrication process, low costs, easy formation of a flexible structure and a wide viewing angle. Therefore, the display technology utilizing organic light emitting diodes has become an important display technology.
At present, the light extraction efficiency of OLED displays is very low. The key reason is that the organic substance has a reflectivity higher than that of glass and air, while glass has a reflectivity higher than that of air, and therefore light emitted by the luminescent layer suffers from total reflection when traveling to the glass and air, resulting in absorption of partial light by the metal electrode. In order to solve this problem, micro-cavity top-emitting OLED displays have been developed, this structure changes light distribution by virtue of the multi-light interference phenomenon inside the organic layer to increase the light extraction efficiency.